[Swift] 如何將字串在全型和半型之間轉換 - 海芋小站

extension String {

    ///轉半形

    var halfWidth: String {

        transformFullWidthToHalfWidth(reverse: false)

    }

    ///轉全型

    var fullWidth: String {

        transformFullWidthToHalfWidth(reverse: true)

    }

    private func transformFullWidthToHalfWidth(reverse: Bool) -> String {

        let string = NSMutableString(string: self) as CFMutableString

        CFStringTransform(string, nil, kCFStringTransformFullwidthHalfwidth, reverse)

        return string as String

    }

}

var str = "Hello, playground"

print(str.fullWidth)

// Ｈｅｌｌｏ，　ｐｌａｙｇｒｏｕｎｄ